Universal Speed Limit
What does time do as an object approaches light-speed?
Time slows down for that object
What kind of relationship does momentum create with speed?
Linear
Define proper length
The length of an object as measured by an observer who is stationary relative to the object
Provide an example of simultaneity
-
Which twin ages less? The one on Earth or the one in space?
The one in space
Name something that can travel exactly at the speed of light
Anything that is massless, like photons, fields, etc
Rest mass remains ____ in relativity
Constant
Define proper time
The time interval between two points as measured by an observer moving at a constant speed
Is simultaneity relative or absolute?
By how much time did the astronaut age less, compared to his Earth twin?
8.6 milliseconds
Who figured out that the speed of light is unique?
OUR friend Albert Einstein
Momentum is conserved unless?
An external stress exists
As the velocity approaches light-speed, the ratio between proper and relativistic length approaches__
Zero
Can two events that are simultaneous in one reference frame not be simultaneous in another moving reference frame?
Yep
From the astronaut's POV, the distance to the star system is ______
Length contracted
Does gravity travel at the speed of light?
Yep
Effects like time dilation and length contraction change how motion is measured
Define Muon
An unstable subatomic particle with an average lifetime of 2.2 μs.
In the railway car, observer 1 (who is stationary on the ground) sees what?
The bolt at the front struck before the bolt at the back.
Why does the astronaut see that Earth ages less?
He sees that Earth disappears and reappears, so Earth’s clock should run slower